docs: def read_hector_constraint(constraint_file):
      """
      Reads a Hector contraint CSV file and returns it as a Pandas Series
      """
      df = pd.read_csv(constraint_file, index_col=0, comment=";")
      df = df[df.applymap(lambda x: isinstance(x, (int, float)))]
      df.index = df.index.astype(int)
      return df.iloc[:, 0]